The mob smashed their way through security fences at the port of Calais.

They overpowered police armed with machine guns and charged past trucks and lorries queueing for the P&O boat. The crew pulled up the ramps and turned fire hoses on the crowd. French police then regained control.

An estimated 2,000 young men, mainly Afghans, Iraqis, Kurds and East Africans, have gathered in the port.

“The ship was delayed by about 45 minutes while a search was carried out in case anyone got on board”

John Bailey, trucker

Trucker John Baileysaid: “The ship was delayed by about 45 minutes while a search was carried out in case anyone got on board.

“Passengers were shocked to see a huge crowd of migrants on the main access road who were being guarded by about 20 French police, some armed with sub-machine guns.

“This was clearly no deterrent as they obviously ran past them into the port, which must have been a distance of about a mile.” But a P&O spokesman insisted the scenes, captured on video, were “not unusual”.

A UK Border Force spokesperson said: “The ramps to the ferries were immediately raised when a number of migrants entered the port, and none of them were able to board.

“The incident was quickly brought under control and the French police apprehended those involved.

“All freight vehicles inside the port at the time have been rescreened by Border Force.

“Security at the UK border is our priority, and we continue to strengthen it.”

The Home Office has lost track of nearly 175,000 illegal immigrants, MPs on the Public Accounts Committee have been told. Committee chair Margaret Hodge said poor security could allow British jihadists to slip back.